I am going to use a JR 400 as the slave for my DX7-does it have to have a battery in it to operate as the slave. My futaba's do not have to be turned on to operate. If the JR does then I need to buy another battery.

Pretty sure its the same, you dont turn the trainer box power on with Spektrum/JR

Hummmmm!! That did not seem to work.

My dx7 manual says if using a JR 72 to set it at ppm. I don't think the sport s400 will allow you to do that. If so, I don't know how to do it.

G'day Mate,
Yes you need a battery in the slave TX, but you don't turn it on with the switch, it comes on, but does not transmit,
when you plug the buddy lead in.
You will need to set all the trims & settings, so that when the trainer switch is operated on the master, no changes occur in the plane, elevators ailerons ect, remain still.
Also the master has to be set as the "Master" & the slave, set as the "Slave".
I don't know if the JR 400 has trainer capabillity, but the manual will explain.

Cheers

Thanks, I do not have the manual but the tx does have a trainer switch on it. The DX7 manual said I have to set the slave to ppm. I don't think you can do that with the R400

are you saying that I have to have a battery in, but don't turn it on. When I hook up the cord then the slave will come but not transmit. If that is so, then off to the store to get a battery. I have always buddy boxed with Futaba. but all of my planes have been changed over to spektrum.
Do you know if the JR400 is PPM. again I don't have a manual, purchased this for a buddy system and it is brand new, no box, no manual

You have probably already gone to the store. Still, I will write that we have used a 9-volt battery, like Duracell, for the slave with the JR radios. However,I can't remember the 400.

Ken Erickson

G'day Mate,
Yes you need a charged battery installed in your TX.
I'm sure the JR400 is PPM, try looking for a manual here, http://www.modelflight.com.au/manuals_jr.htm
Without a pic, it's hard to tell what we are looking for, you have different names for the same radio, that we get over here.
But a JR Quatro, which is 4 channel, is, FM PPM, so try it, it will either work or it won't, simple as that.

Cheers

Here is a picture of the tx.

G'day Mate,
See manual attached, over here it's called a Quattro, looks the same as yours, 4 channel & it is FM PPM.
Be aware, FM PPM is the base system, as they got more advanced they had the option of PCM.
So when it comes to JR, usually, if it's FM, it will be PPM, with the option, if available, of PCM.

Cheers

Thank you Allan. I will get a battery for it and give it a go. We (my wife and I) thinking very hard about a cruise to your country. We have our 50th wedding Anv. coming up this month.

G'day Mate,
Our country will welcome you with open arms, I am in Lightning Ridge at the moment, but we are moving to Attunga, that's about 20 Km's north of Tamworth.
If you Google, Tamworth, you will get an idea where we will be.
Lots of flying going on here all year round.
I hope you can make it.
Drop in anytime & say G'day.

Cheers

I realize its late on this one but just wanted to reinforce what Alan has already posted. The JR two conductor buddy system did require at least a charged battery in both unit units. I have in the past used a 662 and buddied with a 400 or quantro. Their system was nothing like Futabas and most of the others.

John

I don't do much training anymore, however when I did I had Airtronics, Futaba, JR, and Hitec. Still do.

As stated above, JR needs some current outside the Master Transmitter. Now make it easy on yourself. Those small squarish ( 9 Volt small alkaline batts with the snap on tops work as well as one needs.) They are inexpensive and will supply plenty current for the JR buddy box to work.
Radio Shack has snap-on tops available at just a small price. Solder an old JR or such connection to that batt. snap on top. You can figure out how to do that.
They last a long time for keeping the slave Transmitter energized. BTDT!

Something so obvious, I never thought of doing that. Last year we had some batteries out of the clubs buddy boxes stolen. This will prevent that in the future.
Edwin